Evaluation of Morpho-Physiological Traits and Biological Yield in Coloured Cauliflower (Brassica oleracea var. botrytis) Cultivars under Subtropical Conditions of Prayagraj

Abstract

Cauliflower (Brassica oleracea var. botrytis L.) is a nutritionally important and commercially valuable vegetable crop widely cultivated in India, where emerging coloured variants with enhanced antioxidant properties are gaining increasing scientific and market attention. However, limited evidence exists on the morpho-physiological performance and yield potential of these coloured varieties under subtropical agro-climatic conditions, highlighting the need for systematic evaluation. A field experiment was conducted to evaluate morpho-physiological traits governing biological yield performance across ten coloured cauliflower (Brassica oleracea var. botrytis) varieties under subtropical agro-climatic conditions at SHUATS, Prayagraj, Uttar Pradesh, India, during the winter season (December 2024 to February 2025). The novelty of this study lies in the systematic, multi-stage quantification of canopy architecture, SPAD-based chlorophyll content, and biomass dynamics in coloured cauliflower varieties traits hitherto underexplored in the subtropical Indian context. Using a Randomized Block Design (RBD) with three replications, significant inter-genotypic variation was recorded for all measured parameters. At 90 days after transplanting (DAT), canopy cover ranged from 30.12 cm (Poosi) to 43.57 cm (Snow Crown); leaf area varied from 342.55 cm² to 427.98 cm²; chlorophyll content (SPAD values) ranged from 47.28 to 63.77; and biological yield ranged from 510.93 g to 744.93 g per plant. Snow Crown recorded the highest biological yield (744.93 g/plant), associated with the largest canopy cover, leaf area, and chlorophyll content. These results demonstrate that canopy architecture and photosynthetic efficiency are key determinants of biomass accumulation, and that Snow Crown is the most promising genotype for subtropical conditions. The findings provide actionable selection criteria for coloured cauliflower breeding programmes targeting high biological yield under comparable agro-climatic settings.